For the creation of RFC9562 (formally RFC4122) UUIDs
- Complete - Support for all RFC9562 UUID versions
- Cross-platform - Support for ...
- CommonJS, ECMAScript Modules
- NodeJS 16+ (LTS releases)
- Chrome, Safari, Firefox, Edge browsers
- Secure - Cryptographically-strong random values
- Compact - No dependencies, tree-shakable
- CLI - Includes the
uuidcommand line utility - Typescript - Types now included
Note
uuid@11 has the following breaking changes:
- Passing
optionstov1(),v6(), andv7()now behaves slightly differently. See details - Binary UUIDs are now of type
Uint8Array. This may affect code utilizingparse(),stringify(), or that passes abufargument to any of thev1()-v7()methods.
1. Install
npm install uuid2. Create a UUID
ESM-syntax (must use named exports):
import { v4 as uuidv4 } from 'uuid';
uuidv4(); // ⇨ '9b1deb4d-3b7d-4bad-9bdd-2b0d7b3dcb6d'... CommonJS:
const { v4: uuidv4 } = require('uuid');
uuidv4(); // ⇨ '1b9d6bcd-bbfd-4b2d-9b5d-ab8dfbbd4bed'For timestamp UUIDs, namespace UUIDs, and other options read on ...
uuid.NIL |
The nil UUID string (all zeros) | New in [email protected] |
uuid.MAX |
The max UUID string (all ones) | New in [email protected] |
uuid.parse() |
Convert UUID string to array of bytes | New in [email protected] |
uuid.stringify() |
Convert array of bytes to UUID string | New in [email protected] |
uuid.v1() |
Create a version 1 (timestamp) UUID | |
uuid.v1ToV6() |
Create a version 6 UUID from a version 1 UUID | New in uuid@10 |
uuid.v3() |
Create a version 3 (namespace w/ MD5) UUID | |
uuid.v4() |
Create a version 4 (random) UUID | |
uuid.v5() |
Create a version 5 (namespace w/ SHA-1) UUID | |
uuid.v6() |
Create a version 6 (timestamp, reordered) UUID | New in uuid@10 |
uuid.v6ToV1() |
Create a version 1 UUID from a version 6 UUID | New in uuid@10 |
uuid.v7() |
Create a version 7 (Unix Epoch time-based) UUID | New in uuid@10 |
uuid.v8() |
"Intentionally left blank" | |
uuid.validate() |
Test a string to see if it is a valid UUID | New in [email protected] |
uuid.version() |
Detect RFC version of a UUID | New in [email protected] |
The nil UUID string (all zeros).
Example:
import { NIL as NIL_UUID } from 'uuid';
NIL_UUID; // ⇨ '00000000-0000-0000-0000-000000000000'The max UUID string (all ones).
Example:
import { MAX as MAX_UUID } from 'uuid';
MAX_UUID; // ⇨ 'ffffffff-ffff-ffff-ffff-ffffffffffff'Convert UUID string to array of bytes
str |
A valid UUID String |
| returns | Uint8Array[16] |
| throws | TypeError if str is not a valid UUID |
Note
Ordering of values in the byte arrays used by parse() and stringify() follows the left ↠ right order of hex-pairs in UUID strings. As shown in the example below.
Example:
import { parse as uuidParse } from 'uuid';
// Parse a UUID
uuidParse('6ec0bd7f-11c0-43da-975e-2a8ad9ebae0b'); // ⇨
// Uint8Array(16) [
// 110, 192, 189, 127, 17,
// 192, 67, 218, 151, 94,
// 42, 138, 217, 235, 174,
// 11
// ]Convert array of bytes to UUID string
arr |
Array-like collection of 16 values (starting from offset) between 0-255. |
[offset = 0] |
Number Starting index in the Array |
| returns | String |
| throws | TypeError if a valid UUID string cannot be generated |
Note
Ordering of values in the byte arrays used by parse() and stringify() follows the left ↠ right order of hex-pairs in UUID strings. As shown in the example below.
Example:
import { stringify as uuidStringify } from 'uuid';
const uuidBytes = Uint8Array.of(
0x6e,
0xc0,
0xbd,
0x7f,
0x11,
0xc0,
0x43,
0xda,
0x97,
0x5e,
0x2a,
0x8a,
0xd9,
0xeb,
0xae,
0x0b
);
uuidStringify(uuidBytes); // ⇨ '6ec0bd7f-11c0-43da-975e-2a8ad9ebae0b'Create an RFC version 1 (timestamp) UUID
[options] |
Object with one or more of the following properties: |
[options.node ] |
RFC "node" field as an Array[6] of byte values (per 4.1.6) |
[options.clockseq] |
RFC "clock sequence" as a Number between 0 - 0x3fff |
[options.msecs] |
RFC "timestamp" field (Number of milliseconds, unix epoch) |
[options.nsecs] |
RFC "timestamp" field (Number of nanoseconds to add to msecs, should be 0-10,000) |
[options.random] |
Array of 16 random bytes (0-255) |
[options.rng] |
Alternative to options.random, a Function that returns an Array of 16 random bytes (0-255) |
[buffer] |
Array | Buffer If specified, uuid will be written here in byte-form, starting at offset |
[offset = 0] |
Number Index to start writing UUID bytes in buffer |
| returns | UUID String if no buffer is specified, otherwise returns buffer |
| throws | Error if more than 10M UUIDs/sec are requested |
Note
The default node id (the last 12 digits in the UUID) is generated once, randomly, on process startup, and then remains unchanged for the duration of the process.
Note
options.random and options.rng are only meaningful on the very first call to v1(), where they may be passed to initialize the internal node and clockseq fields.
Example:
import { v1 as uuidv1 } from 'uuid';
uuidv1(); // ⇨ '2c5ea4c0-4067-11e9-9bdd-2b0d7b3dcb6d'Example using options:
import { v1 as uuidv1 } from 'uuid';
const options = {
node: Uint8Array.of(0x01, 0x23, 0x45, 0x67, 0x89, 0xab),
clockseq: 0x1234,
msecs: new Date('2011-11-01').getTime(),
nsecs: 5678,
};
uuidv1(options); // ⇨ '710b962e-041c-11e1-9234-0123456789ab'Convert a UUID from version 1 to version 6
import { v1ToV6 } from 'uuid';
v1ToV6('92f62d9e-22c4-11ef-97e9-325096b39f47'); // ⇨ '1ef22c49-2f62-6d9e-97e9-325096b39f47'Create an RFC version 3 (namespace w/ MD5) UUID
API is identical to v5(), but uses "v3" instead.
Important
Per the RFC, "If backward compatibility is not an issue, SHA-1 [Version 5] is preferred."
Create an RFC version 4 (random) UUID
[options] |
Object with one or more of the following properties: |
[options.random] |
Array of 16 random bytes (0-255) |
[options.rng] |
Alternative to options.random, a Function that returns an Array of 16 random bytes (0-255) |
[buffer] |
Array | Buffer If specified, uuid will be written here in byte-form, starting at offset |
[offset = 0] |
Number Index to start writing UUID bytes in buffer |
| returns | UUID String if no buffer is specified, otherwise returns buffer |
Example:
import { v4 as uuidv4 } from 'uuid';
uuidv4(); // ⇨ '9b1deb4d-3b7d-4bad-9bdd-2b0d7b3dcb6d'Example using predefined random values:
import { v4 as uuidv4 } from 'uuid';
const v4options = {
random: Uint8Array.of(
0x10,
0x91,
0x56,
0xbe,
0xc4,
0xfb,
0xc1,
0xea,
0x71,
0xb4,
0xef,
0xe1,
0x67,
0x1c,
0x58,
0x36
),
};
uuidv4(v4options); // ⇨ '109156be-c4fb-41ea-b1b4-efe1671c5836'Create an RFC version 5 (namespace w/ SHA-1) UUID
name |
String | Array |
namespace |
String | Array[16] Namespace UUID |
[buffer] |
Array | Buffer If specified, uuid will be written here in byte-form, starting at offset |
[offset = 0] |
Number Index to start writing UUID bytes in buffer |
| returns | UUID String if no buffer is specified, otherwise returns buffer |
Note
The RFC DNS and URL namespaces are available as v5.DNS and v5.URL.
Example with custom namespace:
import { v5 as uuidv5 } from 'uuid';
// Define a custom namespace. Readers, create your own using something like
// https://www.uuidgenerator.net/
const MY_NAMESPACE = '1b671a64-40d5-491e-99b0-da01ff1f3341';
uuidv5('Hello, World!', MY_NAMESPACE); // ⇨ '630eb68f-e0fa-5ecc-887a-7c7a62614681'Example with RFC URL namespace:
import { v5 as uuidv5 } from 'uuid';
uuidv5('https://www.w3.org/', uuidv5.URL); // ⇨ 'c106a26a-21bb-5538-8bf2-57095d1976c1'Create an RFC version 6 (timestamp, reordered) UUID
This method takes the same arguments as uuid.v1().
import { v6 as uuidv6 } from 'uuid';
uuidv6(); // ⇨ '1e940672-c5ea-64c0-9b5d-ab8dfbbd4bed'Example using options:
import { v6 as uuidv6 } from 'uuid';
const options = {
node: [0x01, 0x23, 0x45, 0x67, 0x89, 0xab],
clockseq: 0x1234,
msecs: new Date('2011-11-01').getTime(),
nsecs: 5678,
};
uuidv6(options); // ⇨ '1e1041c7-10b9-662e-9234-0123456789ab'Convert a UUID from version 6 to version 1
import { v6ToV1 } from 'uuid';
v6ToV1('1ef22c49-2f62-6d9e-97e9-325096b39f47'); // ⇨ '92f62d9e-22c4-11ef-97e9-325096b39f47'Create an RFC version 7 (random) UUID
[options] |
Object with one or more of the following properties: |
[options.msecs] |
RFC "timestamp" field (Number of milliseconds, unix epoch). Default = Date.now() |
[options.random] |
Array of 16 random bytes (0-255) |
[options.rng] |
Alternative to options.random, a Function that returns an Array of 16 random bytes (0-255) |
[options.seq] |
32-bit sequence Number between 0 - 0xffffffff. This may be provided to help insure uniqueness for UUIDs generated within the same millisecond time interval. Default = random value. |
[buffer] |
Array | Buffer If specified, uuid will be written here in byte-form, starting at offset |
[offset = 0] |
Number Index to start writing UUID bytes in buffer |
| returns | UUID String if no buffer is specified, otherwise returns buffer |
Example:
import { v7 as uuidv7 } from 'uuid';
uuidv7(); // ⇨ '01695553-c90c-705a-b56d-778dfbbd4bed'"Intentionally left blank"
Note
Version 8 (experimental) UUIDs are "for experimental or vendor-specific use cases". The RFC does not define a creation algorithm for them, which is why this package does not offer a v8() method. The validate() and version() methods do work with such UUIDs, however.
Test a string to see if it is a valid UUID
str |
String to validate |
| returns | true if string is a valid UUID, false otherwise |
Example:
import { validate as uuidValidate } from 'uuid';
uuidValidate('not a UUID'); // ⇨ false
uuidValidate('6ec0bd7f-11c0-43da-975e-2a8ad9ebae0b'); // ⇨ trueUsing validate and version together it is possible to do per-version validation, e.g. validate for only v4 UUIds.
import { version as uuidVersion } from 'uuid';
import { validate as uuidValidate } from 'uuid';
function uuidValidateV4(uuid) {
return uuidValidate(uuid) && uuidVersion(uuid) === 4;
}
const v1Uuid = 'd9428888-122b-11e1-b85c-61cd3cbb3210';
const v4Uuid = '109156be-c4fb-41ea-b1b4-efe1671c5836';
uuidValidateV4(v4Uuid); // ⇨ true
uuidValidateV4(v1Uuid); // ⇨ falseDetect RFC version of a UUID
str |
A valid UUID String |
| returns | Number The RFC version of the UUID |
| throws | TypeError if str is not a valid UUID |
Example:
import { version as uuidVersion } from 'uuid';
uuidVersion('45637ec4-c85f-11ea-87d0-0242ac130003'); // ⇨ 1
uuidVersion('6ec0bd7f-11c0-43da-975e-2a8ad9ebae0b'); // ⇨ 4Note
This method returns 0 for the NIL UUID, and 15 for the MAX UUID.
UUIDs can be generated from the command line using uuid.
$ npx uuid
ddeb27fb-d9a0-4624-be4d-4615062daed4The default is to generate version 4 UUIDS, however the other versions are supported. Type uuid --help for details:
$ npx uuid --help
Usage:
uuid
uuid v1
uuid v3 <name> <namespace uuid>
uuid v4
uuid v5 <name> <namespace uuid>
uuid v7
uuid --help
Note: <namespace uuid> may be "URL" or "DNS" to use the corresponding UUIDs
defined by RFC9562As of uuid@11, all timestamp-based UUID APIs (v1(), v6(), and v7()) now operate in two distinct modes:
- Without
options: If nooptionsargument is passed, these APIs will make use of internal state such as a sequence counter to improve UUID uniqueness. - With
options: If anoptionsargument of any kind is passed, no internal state is used or updated. Instead, appropriate defaults are used. See the respective APIs for details.
Prior to uuid@11, this distinction was less clear. Internal state was was being combined with options values in ways that were difficult to rationalize about, and that could lead to unpredictable behavior. Hence, this change.
Markdown generated from README_js.md by